Field of the Disclosure
This application relates generally to improvements to a seat arrangement structure. More particularly the present disclosure relates to improvements seat slide device optimally applied for an automotive vehicle, and specifically related to a power seat sliding mechanism with a walk-in mechanism means for creating a space necessary for getting in and out the car.
Description of the Related Art
Vehicle seats are designed to offer comfort, and space to an occupant by allowing seat adjustments to a desired position. The adjustable vehicle seat allows an occupant to obtain a more comfortable seating position and to provide space behind, in front or on side of the vehicle seat to assist in entering and exiting the vehicle or storing objects.
Vehicle seats are typically mounted on a sliding device such as a sliding rail system. The seat sliding device and mounting are often a complex assembly, as it involves various components assembled in a particular order to enable seat movement in desired direction. One of the components of the seat arrangement device is a track arrangement fitted with a sliding arrangement to achieve the desired lateral and longitudinal movement of the seats. The lateral movement involves moving a seat towards a side of a vehicle or moving the seat towards the other seat followed by locking the seat in a desired position. Further, to lock the seat in a desired position a locking or latch mechanism is provided.
In the seat sliding device described in a published U.S. Pat. No. 5,516,071, the seat sliding device can be fully manually operated, for example using a handle under the seat or can be power assisted with a manual walk-in mechanism. A typical power operated seat includes a lead screw and nut arrangement installed within the tracks. The nut or the lead screw may be driven by a motor which results in a slow relative movement between the lead screw and the nut which is translated into seat movement. Further, a rotating type of lock is employed to lock the seat in desired position. Typically, a power operated sliding system is locked into place by the nut holder and lock lever teeth. Improving the lock strength of the teeth is desirable to improve safety. Traditional systems may also lack vertical looseness control which could prevent teeth bending and accidental unlocking. The rotational lock may also extend far below the lower rail which may cause packing constraints closer to the floor within the vehicle.
In the seat sliding device described in a published U.S. Pat. No. 7,303,223, the walk-in mechanism has a floating lead screw and fixed control nut. The nut is originally fixed to the lower rail while the lead screw is rotating through it allowing the upper structure to move forward and backward. Once this system is applied, the nut is fixed to the lower rail by lock lever. However, when the lock lever is released the nut is no longer constrained and therefore, the upper structure along with the nut is freely sliding forward resulting in a walk-in operation.
Thus, there is a need to resolve the above mentioned issues related to the walk-in mechanism. Additionally, there is a constant need to improve the seat sliding device and its performance.